Probe to plunge into sun's atmosphere

Emma Woollacott, 3rd September 2010

In a project reminiscent of Prometheus' theft of fire from the gods, NASA's planning to dive into the sun and capture some of its atmosphere.

Slated to launch no later than 2018, Solar Probe Plus will get as close as four million miles to the sun’s surface - far closer than ever before.

"The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics - why is the sun's outer atmosphere so much hotter than the sun's visible surface, and what propels the solar wind that affects Earth and our solar system?" said Dick Fisher, director of NASA's Heliophysics Division. "We've been struggling with these questions for decades and this mission should finally provide those answers."

NASA's selected several projects for investigation.

One will count the most abundant particles in the solar wind - electrons, protons and helium ions - and measure their properties. The project will also involve an attempt to catch some of the particles in a special container for direct analysis.

The Wide-field Imager will observe the solar wind and provide 3D images of clouds and shocks as they approach and pass the spacecraft.

In another project, direct measurements will be made of electric and magnetic fields, radio emissions, and shock waves within the sun's atmospheric plasma. The experiment will also serve as a giant dust detector, registering voltage signatures when specks of space dust hit the spacecraft's antenna.

And two instruments that will take an inventory of elements in the sun's atmosphere using a mass spectrometer to weigh and sort ions near the spacecraft.

"This project allows humanity's ingenuity to go where no spacecraft has ever gone before," said Lika Guhathakurta, Solar Probe Plus program scientist. "For the very first time, we'll be able to touch, taste and smell our sun."

The mission has been a long time in coming. A probe into near-Sun particles was first recommended in 1958 by the National Academy of Science’s Simpson Committee.